Cam-lever timing block with connections



Feb. 12, 1924. A. 'A. ASPLUND CAM LEVER TIMING BLOCK WITH CONNECTIONS ori inal Filed Feb. 17. 1920 anvgwtoz Axel A-Asfilund mumm Patented Feb. 12, 1924.

AXEL nueusr ASPLUND, or AUBURN, NEW YORK.

CAM-LEVER TIMING BLOCK WITH CONNECTIONS.

Application filed February 17, 1920, Serial No. 359,410. Renewed July 21, 1923.

To all whom it may concern: I A Be it known that I, AXEL A. AsrLUND, a citizen of the United States, residing at Auburn, in the county of Cayuga and State of New York, have invented certain new and useful Improvements in Cam-Lever Timing Blocks with Connections; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertaius to make and use the same.

This invention relates to internal combustion engines, and while particularly. adapted to what is known as the Diesel type of internal combustion engines, is not limited thereto. The invention specifically relates 'to cam lever timing blocks.

An object of this invention is to provide a means for'compensating for the action of the usual eccentric used on the modern engine, which eccentric is provided for lifting the cam engaging members or timing rollers from the camSduring the reversal movement; that is to say during a movement of the rollers relative to the cams or the cams relative to the rollers in changing the cams in a reversing operation. In the modern Diesel engine it is usually the custom to provide a plurality of cams upon the cam shaft, the cams being in duplicate in juxtaposition and the duplicate cams being operative of the same valve. These duplicate cams are mounted on the same shaft at a relative angularity to each other so that bythe shifting of one of these cams under the roller the timing is accomplished to open the valve for a forward movement and by theshifting of the other cam under the roller the valve is opened for a .rearward movement. In order to accomplish this shifting of the cams it is customary to provide on the cam lever or rocker shaft which is adjacent'to the cam shaft, an eccentric which by the turning of the cam lever shaft lifts the timer rollers from the cams prior to this shifting operation. The movement of this eccentric on the cam lever shaft varies the position of the roller relative to its normal engagement with the cam, and since the engine is still running during this reversing operation and before the roller is entirely lifted from the cam, it disarranges the predetermined timing frequently causing serious trouble. It

Diesel with respect to cam timing lever 3 is an object of this invention to provide a means for compensating for the movement of the cam lever by this eccentric in direc- I tions other than those desired for the lifting of the cam and to keep the cam roller at the same distance from the center of the cam shaft during this lifting operation.

With these and other objects in view the invention consists in the construction, the combination, the detail and arrangements of parts as hereinafter more fully described and claimed.

In the drawings Figure 1 is a side elevation. of a cam lever of this improved design attached to a fuel valve.

Figure 2 is, a side elevation ofa cam lever of this design attached'to a starting valve.

Figure 3 is a section through the cam lever shown in Figure '1 showing the timing block partly in plan and partly in section.

Figures 4, 5, 6, 7 and 8 are details of the parts shown in Figure 3.

Fig. 9 is a detail of an adjustable device connecting the cam lever with the fuel valve operating lever. Y 1 I i In detail this invention consists in a slide comprising the timing block 2 and its mount in cam lever 3 and connecting link in the form of a strap 4:, pivoted concentrically lever shaft 5. This application is one of'a set of seven independent applications filed simultaneously, the valve illustrated in Figure 1 and connect ing means to the cam lever and also the specific form of cam lever and valve connection and the valve illustrated in Figure 2 being covered in separate applications, copending with the one herein. As illustrated more in detail in Figure 4, cam lever 3 is provided with a longitudinal guiding surface in the nature of a groove or slot 5 to receive timing block 2, the cam lever also being provided with a bore 6 and *tapped holes 7 in which cap screws are 1nsorted in mounting a retaining plate 8 for retaining said timing block 2 in said slot 5 and permitting it to slide longitudinally therein. Timing block 2 is provided with a hole 9 timing block 2 and strap 4; "Strap 4 is mounted concentric relative to shaft 5 and is mounted eccentric relafor receiving a stud 10. which stud 10 provides pivotal connection'between tive to shaft 5, both being mounted upon.

. with respect to said arc described by proved result, it

ments. of s i a collar 11 shown in side and end elevation in F .igure 7. That is to say strap 4 is mounted on the smaller bearing sur face in said collar 11, which is concentric to its bore, and lever 3 is mounted upon the longer surface, which is eccentric relative to its bore, its borebeing such as to fit upon shaft 5 and being aflixedthereto by a key. The turning of shaft will cause the cam lever 3 to have a movement about an axis eccentric with respect to the axis of shaft 5, but by reason of the sliding of block 2 in lever 3 due to the fact that strap 4 connected with block 2,.is pivoted concentric shaft 5; the roller .12 mounted in block 2 will :always have its center the same distance from the center of shaft 5 irrespective of the movement of lever 8 about said axis that is eccentric relative to shaft 5. Obviously if the com pensating means herein specified were not provided and said shaft 5 were rotated in a clockwise direction (as viewed in Figure 1) through an arc of 90 from adownward position of the eccentric as shown in Figure 7, the center of the roller .12 would move to the left substantially the normal throw of the eccentric and this would cause the raised portion 13 of the cam-14 if it were rotating in a-clockwise direction to preengage roller 12 relative to its normal engagement to a considerable extent, as, for instance, if the throw of the cam were throughout a half circle an inch and one quarter there would be a substantial variation of five eighths of an inch of this roller from the vertical line in 90 and quite a considerable fraction ofthis variation prior tothe full lifting of the said roll-er fromthesaid cam. This would cause trouble especially with the fuel valve, which is normally set to open a tiny fraction of time before upper limit of piston movement is reached and which, by reason of this eccentricity, would be opened a relatively large fraction of time before the upper limit of piston movement and might occasion the rupturing of the crank shaft or other break-age or straining of the engine by reason of a premature combustion. Whereas, in the improved means described relative change of position is very slight, being only equal to the fraction of the radius outward from the chord of the small the angular movement of said cam roller. More specifically referring to the method of accomplishing this imwill be observedzthat timer block 2 which slides freely in slot 5 can have no movement relative to lever 3 ex- .(iept a radial movement with-respect to axis of said lever, and by reason of the fact that block 2 is held from radial movement relative to shafto by strap 4, the varying movelever 3*:with; respect to S id on its upper face with the 1. sses? shaft 5 cause a relative sliding movement between block 2 and lever 3 and cause the center of roller 12 mounted on block 2 to substantially describe an are about the axis of shaft 5 having a constant radius.

Applicant has herein illustrated the application of his improved compensating de vice to two types of valve levers. In Fig ure 1 a fuel valve is illustrated in which the eccentrically operated part 3 of the lever is shown pivoted as at 41 to a stud 22 which is in turn pivoted at 23 to a lever 24 adapted to engage and operate the valve stem. In Fig. 2 applicant shows the present invention applied to a. starting air and pressure relief valve in which the eccentric operated part of the lever 3 i shown flexed spring 15 secured by nut 16 to a bracket 17 and also flexed with regard to the noneccentric part of the lever by means of spring 18 and stud 19. In this type of valve lever it will be noted that the rear end 3 of lever 3 is left free and provided a wedge-shaped slide J which is adapted to be drawn under roller 20 by the forwardtransverse motion imparted by eccentric 11 operating to depress the valve stem during this stage, of the operation to relieve the pressure in the cylinders as more fully set forth in m pending application Serial No. 359,.i15.

Another advantage of construction herein disclosed is that by the removal of stud 10 the timer block 2 can be quickly withdrawn thus admitting-of a this timerblock downward movement of lever 3 withouten gaging .the cam and thus enabling thequic-k removal of the valves in the engine, which. heretofore has been extremely diflic-ult with a single member comprising theca-m lever since it was obstructed from downward,

movement by the cams necessitating theremoval of parts difficult to remove in order to obtain accessto the valves.

Claims:

I. In a timer havin a cam lever shaft wvith {an eccentric for lifting a cam lever mounted thereon, a timer block slidable in one end ofsaid cam lever, and a link connecting said time-r block with the lever shaft to retain the timer block at a constant radial distance therefrom.

2. In combination, a cam lever shaft, a. cam lever eocentrically mounted on the lever shaft, a timer block slidable in the cam lover, and a link conccntrically mounted on l'he lever shaft and connected with the timer block.

3. In mechanism of the class described, combination of a revoluble cam, an angularly adjustable shaft having an eccentric, a lever journaled on said eccentric, a block slidably meunted with respect to the lever. said block-carrying a cam engaging member, and means for holding the cam engaging member in substantially the same angular relation with respect to the axis of the cam in all adjustments of said eccentric.

4. In mechanism of the class described, the combination of a cam, an angularly adjustable shaft carrying an eccentric, a lever journaled on said eccentric, a link pivoted concentrically with respect to the said shaft, a timer block connected to said link, a timer member on said timer block adapted to engage said cam, said timer block being slidably mounted on said lever.

5. In mechanism of the class described, the combination of a cam, an angularly adjustable shaft, an eccentric on said shaft, a lever journaled on said eccentric, said lever having a longitudinal groove, a timer block slidably mounted in the groove in said lever, a timer member carried by said block, a link pivoted to said block and concentrically pivoted with respect to said shaft.

6. In mechanism of the class described, a timing cam, a timing lever adapted to be rocked by said cam, an adjustable fulcrum for the lever adapted to free the lever from engagement with the cam, a contact member movably mounted on said lever, and means for maintaining the contact member in substantia-lly the same timing relation with respect to the cam throughout adjustments of the fulcrum.

7. The combination with a cam, a lever carrying a cam engaging member, and a pivotal bearing for the lever, of means for varying the center of the pivotal bearing and means for maintaining a constant relation between the cam and the cam engaging member.

8. A cam lever, having a transverse bore for mounting the same, a sleeve rotatable in said bore, a bearing shaft eccentrically mounted and secured in said sleeve, said sleeve provided with a seat concentric with said shaft, a slide on said lever, said slide carrying a contact member at one end and having a bore adapted to seat on said concentric seat on the sleeve.

9. The combination of a lever, a slide on said lever carrying a contact member and means for pivotally mounting said lever and slide on a common pivot member, said lever being mounted eccentrically and said slide bein mounted concentrically of said pivot mem er.

In testimogiy whereof I aflix my signature.

A EL AUGUST ASPLUND. 

